1. Technical Field
This disclosure relates to a speech enhancement, and more particularly to enhancing speech intelligibility and speech quality in high noise conditions.
2. Related Art
Speech enhancement in a vehicle is a challenge. Some systems are susceptible to interference. Interference may come from many sources including engines, fans, road noise, and rain. Reverberation and echo may also interfere in speech enhancement systems, especially in vehicle environments.
Some noise suppression systems attenuate noise equally across many frequencies of a perceptible frequency band. In high noise environments, especially at lower frequencies, when equal amount of noise suppression is applied across the spectrum, a higher level of residual noise may be generated, which may degrade the intelligibility and quality of a desired signal.
Some methods may enhance a second formant frequency at the expense of a first formant. These methods may assume that the second formant frequency contributes more to speech intelligibility than the first formant. Unfortunately, these methods may attenuate large portions of the low frequency band which reduces the clarity of a signal and the quality that a user may expect. There is a need for a system that is sensitive, accurate, has minimal latency, and enhances speech across a perceptible frequency band.